Data commit

Task/Mandelbrot-set/Erlang/mandelbrot-set.erl

@@ -0,0 +1,50 @@
+-module(mandelbrot).
+
+-export([test/0]).
+
+magnitude(Z) ->
+  R = complex:real(Z),
+  I = complex:imaginary(Z),
+  R * R + I * I.
+
+mandelbrot(A, MaxI, Z, I) ->
+    case (I < MaxI) and (magnitude(Z) < 2.0) of
+        true ->
+            NZ = complex:add(complex:mult(Z, Z), A),
+            mandelbrot(A, MaxI, NZ, I + 1);
+        false ->
+            case I of
+                MaxI ->
+                    $*;
+                _ ->
+                    $
+            end
+    end.
+
+test() ->
+    lists:map(
+        fun(S) -> io:format("~s",[S]) end,
+        [
+            [
+                begin
+                    Z = complex:make(X, Y),
+                    mandelbrot(Z, 50, Z, 1)
+                end
+            || X <- seq_float(-2, 0.5, 0.0315)
+            ] ++ "\n"
+        || Y <- seq_float(-1,1, 0.05)
+        ] ),
+    ok.
+
+% **************************************************
+% Copied from https://gist.github.com/andruby/241489
+% **************************************************
+
+seq_float(Min, Max, Inc, Counter, Acc) when (Counter*Inc + Min) >= Max ->
+  lists:reverse([Max|Acc]);
+seq_float(Min, Max, Inc, Counter, Acc) ->
+  seq_float(Min, Max, Inc, Counter+1, [Inc * Counter + Min|Acc]).
+seq_float(Min, Max, Inc) ->
+  seq_float(Min, Max, Inc, 0, []).
+
+% **************************************************